CONTROL GP-ELECTRONIC 2867039 - Caterpillar

(3XF),
G3608 (4WF) 3612 (1YG),
G3616 (4CG) EnginesProblem:
There have been reports of nuisance "No Mag Interface" shutdowns on these engines. When this shut down occurs:* The "F9" light is activated on the Engine Supervisory System (ESS) control panel.* The "No Magneto Interface Signal" light is activated on the Timing Control Module (TCM).* Diagnostic Code (326-09) is activated on the Digital Diagnostic Tool (DDT).The "No Mag Interface", (326-09) is activated by the Timing Control Module when no ignition pulses are received from the Magneto Interface Box. This diagnostic is only detected when the engine is started and the speed is between 120 and 300 rpm. If no ignition pulse is detected for 500 milliseconds after the engine speed is greater than 120 rpm and less than 300 rpm, the engine is shut down.Solution:
Because the ignition pulses are present when the shutdown occurs, these nuisance shutdowns appear to be the result of: system grounding; the voltage threshold in the Timing Control Module; and/or the voltage levels generated by the Magneto Interface Box. A permanent fix is being worked on, and will be released when identified. An interim fix that will reduce the frequency of these nuisance shutdowns follows:Use an 18 gauge wire to connect terminal 545 (located on the door of the ESS panel) to terminal 354 or 353 [battery negative (located in the lower right corner of the ESS panel box)]. Reference 3E-9347 or 128-2508 Electrical Wiring Diagram for in-line engines. Reference 3E-9348 or 128-3198 Electrical Wiring Diagram for vee engines.COPYRIGHT 1997 CATERPILLAR ALL RIGHTS RESERVED